1. Field of the Invention
This invention relates generally to forming materials and more particularly to hemming or flanging of metal sheets. A hemming or flanging process forms a flange on the edge of a metal sheet. Folding the formed flange onto the metal sheet conceals the cut edge and completes the hem.
2. Description of the Related Art
A device for flanging metal sheets is disclosed in DE 19801561. In this patent, an electromechanical operation of the flanging bed for the displacement stroke between the flanging jacks and the operating stroke is proposed. The flanging jacks are placed in a pivoting manner at the machine frame and are moved by means of pneumatic cylinders. For a tool change, the flanging jacks, flanging bed, and hold-down clamps must be individually assembled, disassembled, and adjusted. These operations are very time consuming and lead to very long downtimes when a change is required. Maintenance work requires the same laborious operations and the flanging device remains inoperative during any preventive maintenance procedures.
Electro-mechanical drives have also been used to improve upon some of the noise characteristics associated with the hydraulic drives of flanging devices. DE 19747291 discloses a device for folding metal sheets that performs the work stroke by means of pneumatic air cushions with the air cushions acting directly on the ram for the folding process. A disadvantage of this design is that the folding device is a component of the drive unit thereby involving the drive unit during a tool change.
There exists a need for a hemming/flanging device that reduces maintenance time and simplifies the flanging tool change procedures.
Accordingly, the present invention overcomes the problems of the prior art by providing an apparatus for flanging together metal sheets in a manufacturing process. The apparatus comprises a base frame, a flanging bed operative to move from a first position to a second position, and a flange drive operative to move said flanging bed. A flanging jack is disposed upon the flanging bed. The apparatus further includes an exchangeable flanging tool, the tool including the flanging bed and flanging jack, mounted on the base frame as well as a flanging tool base including slidable members therein. The exchangeable flanging tool is disposed on the slidable members such that a first exchangeable flanging tool can be slidably removed and replaced by slidably moving a second exchangeable flanging tool into place.
It is advantage of the current invention to simplify drive maintenance procedures by incorporating the main flanging tool-specific components, especially the flanging bed and the flanging jacks, into the flanging tool and mounting the tool on the base frame as an exchangeable unit.
Furthermore, it is an advantage of the current invention to establish the flanging tool as an independent, transportable unit. The tool maintains its workpiece specific settings and adjustments regardless of whether it is located in the flanging device. Thus, for tool maintenance and tool change, the flanging tool can be quickly and easily removed from the flanging device and replaced by another flanging tool.